Robbie Keane must be a regular in the Tottenham starting line up this season if the club are to crack the top four, according to former player Ossie Ardiles.

Spurs manager Harry Redknapp installed Keane as captain following the striker's return to White Hart Lane last season after an unhappy spell at Liverpool.

The Republic of Ireland man's place in Redknapp's starting line up had been in doubt following the £9million capture of Peter Crouch from Portsmouth.

Crouch and Spurs striker Jermain Defoe formed an effective partnership at Pompey when Redknapp was in charge before the 62-year-old swapped the south coast for north London last year.

But Ardiles believes captain Keane must be a regular fixture in the Spurs starting XI this year, despite stern competition from Crouch, Defoe and Roman Pavlyuchenko.

"It's very important that Robbie is playing this season. He is one of the most important players for Spurs and if he has a good season then Spurs will be right up there," Ardiles told Press Association Sport.

"I like Robbie very much. Not only is he a very intelligent player, but he also plays with his heart and I like that.

"He is the captain of the club, he is the emblem of Spurs so he will be playing regularly.

"I don't expect him to be on the bench, I expect him to be playing all the time."

Despite suggestions that Crouch and Defoe will lead the line this year, Ardiles believes that the pair can also team up with Keane to form a deadly trio capable of improving on the 45 goals the north London team managed last term.

"Maybe he will play with two front players in Crouch and Defoe with Robbie playing a little bit behind them," said Ardiles, who won two FA Cups and one UEFA Cup with Spurs between 1978 and 1988.

"Maybe it will be a better position for Robbie because he is not an out-and-out striker.

"Crouch is another option up front with his height and he's pretty good with his feet as well," he added.

"Harry now has Jermain Defoe, Robbie Keane, Crouch and Pavlyuchenko so he has lots of choices and the more choices you have, the better it is."

Redknapp has set his squad the tough challenge of breaking the stranglehold that Manchester United, Liverpool, Arsenal and Chelsea have on the Premier League top four.

Everton are the only team to manage that feat in the last six years but Redknapp has signed England striker Crouch, Sebastien Bassong, Kyle Walker and Kyle Naughton this summer to help his cause.

Ardiles now believes the former West Ham boss has the squad capable of breaking the monopoly of the Big Four.

"I think Tottenham can finish in the top four. That's what Harry wants, it's what all the fans want and I think they are well equipped enough to do it," said the Argentinian at the launch of his autobiography, Ossie's Dream.

"Tottenham have a big squad and you need that in the Premier League and if you don't have, you will suffer.

"In the last few seasons the top four have always been the same and now this season I think it can change.

"Manchester United will miss (Cristiano) Ronaldo, Arsene Wenger has not added to his squad very much and Liverpool rely too much on Gerrard and Torres so it will be much more competitive and either Manchester City or Tottenham can come into the top four."